Hydroxy-substituted aryl guanamines



' ordinarily cheap and easy to prepare. 7 esters, however, such as the esters ofether alco- 55 Patented Oct. 9. 1945 lflnltoxr-ispnsrrro'mn ARYL.

Jack Theo Thurstom Cos Cob, Conn, assignor to American No Drawing. Application Ali-gust som day Serial No. 409,140; :f

, Gyanamid Company, v I N. 1., acorporation of Maine:

New York,

4 Claims. (01. acts-crash This invention relates to hydroxy-substituted aryl guanamines and methods of making them.

Several unsubstituted: aryl guanaminesiihave been made by rather laborious; processes low yields, such as .iorexamine, benzmguanami-ne. Thesefguanamines; however, 1' are restricted in their field rof zutility ibecause, when used for? making" resins'by condensation' witlr formaldehyde, the resinsare colorless-andhence have'toicompete with numerous: otheramino plastics; somtof which are-available 'ati mncl'r lower prices; The

hydroxyiaryl guanamine however; havaim'p'ortant additional properties; in that, most cases, the-hydroxy group. renders: the aromatic portion of the :guanamine capable .oftouplirrg witltdiaz'o compounds torformiazoi dyes. whichthe guananiineis a portio'nfof thedye-moleculajswhen suchfdyes are combined with formaldehyde. to :Eorrn resins, tha'resin' its'ett is-. co1'o'red' and requires no additional:color.v Verys'ctesirabla colored ripl a's tics and films can thus bei producedg and Ithi a is an important new field which isiopen toithezproducts =of' the present, invention. J Itshould be un- 'derstood,.ihowever; that while the production of colored rfesin's forms animportantfleldiot'iitility forthe hydroxy-substituted aryl g'uanamines of the present inventiomgitis. not-t e only use; and

' the invention isinno sense-limited: :toa any single many: oi the hy ro y :arylsr guanarmneszcan :be i

prepared withou :the need: tofiziany Especial; Footidensing en s- 1 'Imsomejcaseste ndensingagents 'suchxas:zmetalqalkoxidea maybe emnl yedtmacceleratee he reactien; orto-opviatesaltziormation -Withrthcibiauanide;in ithegcase of hydroxy substituted aryl esters which also have other strongly negative substituents.

In the preferred process described above, the particular alcoholic radical in-the ester is not of vital importance, and broadly, any ester may be employed. In general, however, I find that the esters of' the low molecular monohydric parafiin alcohols give excellent results and are Other hols oflthe ethylene "glycol '"etherfltype @and the phenolic typemayalso be' employed. p

It isdesirable-to carry out theprocess of preparingthe hydroxyar'yl 'guanamines of the-pres ent inventioninthe presence Oran organic solvent or diluent; Any su-itable'solvent may be -'us'e d but lf'ha-ve found that the bestfresults hayebeen obtai'nedwith alcohols as solvents. Here again, any alcohol may be used which has adequate solvent action for the big-uanide' in questiqnl general, the lower monohydric paraffln 'alcqhols such as methanol and ethaholare'effective as'jare the lower molecular-ether alcohols si lch as the ethyletherof ethylene glycol; "While -in;;n o sense essential, it is 'conven-i'ent'to use an alcohol solvent correspondingto the alcohol radical of the ester used, because inthereaction the alcohol is formed anagwhen the two are the same, no separation problem isinvolved.

.The most important hydroxy-substituted aromatic guanamines of the present invention are those prepared withbiguanide in which case the tri-azine ring is substituted by two amino groups. .H w verpth j invention is not limited. o such 1 uanamines; on, the. contrary, -N,-.substit1 1ted auanamih s may be prepared ,andi-n some QfiSfis are 1 pr ducts of l considerable .ir raotical Y mpo tanc They areea il iimade by usin he, corr sn ndina (su s itut d; bieuam de. such. as. pheny biguanide', 'al-lylhiguanidaland the, like, althqll h vthe react on is omen notlas rapid as-wi h 'uani e itself, and it is treqllently desirablq toluse a con-- densingagimtsuchasa metal-alkoxide -15. 511911.10.

be oted that.- the use. ofa conden in asent;.suh s .a metal iallcoxideis not cl imed .--lbroadlyn this case, but only in conjunction with the preparation of hydroxy substituted aryl guan-amines to which themesentcaseprimarily relates.

" Examp Z-hydroxybenzoguanamine One hundred and thirty-one parts of biguanide were dissolved in 400 parts of methanol. Thereupon 228 parts of methyl salicylate were added and the solution filtered. After standing overnight the guanamine had precipitated and Was removed by filtration. On further standing, the filtrate deposited more guanamine, which was combined with the main product and was further The product was in the formof small Example 2 2-hydroxy-3-nitrobenzoguanamine parts of methyl alcohol, the solution was filtered.

and then a solution of 29.2 parts of coumarin dissolved in 80 parts of methyl alcohol were added. Reaction took place slowly and was speeded by the addition of a small amount of sodiummethoxide. The solution was acidified with acetic acid and evaporated, giving a yellow solid which was boiled with water, filtered, and

- finally dissolved in the ethyl ether of ethylene less than owing to salt formation which inparts of methanol and to the filtered solution 'lar equivalent standing overnight the guanamine had partially.

melted, at 218 C., the yield being justunder 45%. 55

glycol. On dilution with an equal volume of naphtha, fine light yellow needles, melting at I I] OH NO: 296"C., were precipitated. The yield was about HzNO o v I r N NE: 1 I Example 5 20.2 parts Of biguanide were dissolved 4-hydrbxy-3-sulfobenz guanamine parts of methanol and the solutionwas filtered- 42 parts of methyl nitrosalicylate dissolvedin about 175 parts of methanol were then added.

- N N so H After mixing, the solution became blood red and H N I ll NH 3 an orange precipitate formed which was the r biguanide salt of methyl 3-nitrosalicylate. A N

molecular equivalent of sodium metal was dissolved in about 800 parts of methanol and added to the above biguanidesalt, solution forming a blood red solid. This reaction mixture was stirred and refluxed for about two hours and then diluted with water, acidified with acetic acid. The precipitated product was filtered and purified by dissolving in the ethyl ether of ethylene glycol and. diluting with a mixture of methanol and water. Minute yellow plates melting at 296 C. were obtained. The yield was somewhat Thirty parts of biguanide were added to 42 parts of the potassium salt of methyl 3-sulfo- 4-hydroxybenzoate dissolved in about 750 parts of methanol. After standing for some time the reaction product did not precipitate from the solution. Uncombined biguanide was precipitated by adding an excess of a copper sulfate solution and filtering, in order to remove the insoluble biguanide copper sulfate salt. The filtrate was then freed of copper by means of hydrogen sulfide followed by filtration, and the filtrate concentrated to a viscous mass under reduced pressure. The excess sulfuric acid was removed by digestion with 200' parts of ethanol, leaving a colorless solid, which on recrystallization from water gave colorless plates melting at about 326 0., the yield being about 10%. As in the preceding example, the yield is adversely affected by salt formation.

What I claim is:

LA method of preparing a hydroxy-substituted aryl guanamine which comprises the steps of dissolving a biguanide in a suitable solvent therefor, adding thereto an ester of a hydroxysubstituted mono-nuclear aromatic carboxylic acid, carrying the resultant reaction to substantial equilibrium and isolating the resultant hydroxy-substituted aryl guanamine.

2. A method of preparing a hydroxy-substi- .tuted aryl guanamine which comprises the steps of dissolving biguanide in a suitable solvent therefor, adding'thereto an ester of a hydroxyhibited the production of guanamine.

' Example 3 2-hydroxymethylbenzoguanamine mN-o O-NH: l

N I 20.2 parts of biguanide were dissolved in 80.45

was addedv 28.2 parts of phthaliderdissolved in 80 parts of methanol, together with the molecuof sodium methoxide. After precipitated and within. one-half hour after scratching the sides of the reaction flask, there was a voluminous precipitate. The product was recrystallized from water containing a small amount of ammonia and the plate-like needles acid, carrying the resultant reaction to substantial equilibrium and isolatingthe resultant hydroxy-substituted aryl guanamine.

3. A method according to claim 1 in which the reaction is carried out in the presence of a lower monohydrlc paraffin alcohol as a solvent.

4. A method according to claim 2 in which the reaction is carried out in the presence of a lower monohydric paraflin alcohol as a solvent.

' JACK THEO THURSTON.

Example 4 2-hydroxycinnamoguanamine N 21.2 parts of biguanide were dissolved in 6 substituted mono-nuclear aromatic carboxylic 

